Axially movable turbine for varying the turbine inlet in response to speed



1953 R. 'r. DE MUTH EI'AL 3,073,117

AXIALLY MOVABLE TURBINE FOR VARYING THE TURBINE INLET IN RESPONSE TO SPEED Filed April 1, 1958 SOLID PROPELLANT INVENTORS. RUSSELL T. DEMUTH DONALD M. LAWRENCE Wain,

ATTORN EY United States This invention relates to gas turbine-driven devices and more particularly concerns a gas turbine having a control which regulates the speed of the turbine.

An object of the present invention is to provide an improved compact gas turbine and control therefore whereby the rotating speed of the turbine is held at a predetermined rate without the use of valves.

Another object is the provision of such a turbine in which there is a speed-responsive mechanism which axially moves the turbine and thereby controls the supply of pressurized gas to the turbine.

Another object is to provide a turbine and servo control in which an unbalancing of the pressures on the sides of the turbine is effected and the turbine is moved axially so that a predetermined speed is maintained.

A further object is the provision of a turbine having means for the control of turbine speed in which the driving gas is used to move the turbine axially by unbalancing the pressure on parts of the sides of the turbine.

Another object is the provision of an improved turbine unit in which gases from a gas-generating cartridge are fed to a pin-wheel turbine through an axial nozzle which is cleaned and protected by an extension and bafile plate connected to the turbine.

The accomplishment of the above objects and the features and advantages of the present invention will be apparent from the following detailed description and the accompanying drawing of an embodiment of the invention and in which:

FIG. 1 is a longitudinal cross section through a gas turbine driven power supply unit having a pin-wheel turbine and cartridge gas generator with the cross section showing an outlet and a radial passage of the turbine, and

FIG. 2 is a transverse cross-sectional view through the turbine section along the line A-A of FIG. 1 and shows the face and the passage grooves-of the turbine wheel member.

Referring to the drawings, there is disclosed a housing 11 having a casing 13 threaded in one end thereof. The casing 13 contains a solid propellant 15. This ammonium nitrate cartridge is ignited by a conventional wire type igniter (not shown) which is adapted to be energized by the electrical connectors 17 in the end wall of the casing 13 and is arranged to ignite the inner face of the cartridge. A cylindrical chamber 19 at the inner end of the cartridge collects the gases generated by the solid propellant 15. In chamber 19, there is an annular baffle 21 which forms a narrow transverse annular passage 23 with the transverse housing wall 24. Baflle 21 is carried by an axial extension 25 from the turbine wheel 27 and is attached to left end thereof by a lock nut. The passage 23 leads to a conical gas passage 29 which surrounds the turbine extension 25. The converging gas passage 29 is formed in the axial part of the transverse housing wall 24 which has an axial projection 31 extending toward the front side of the turbine wheel 27. The turbine 27 is positioned in chamber 32 formed by housing 11 and another tubular housing 33. Exit or exhaust ports 34' for the gases from the turbine are provided in the left end of housing 33.

The pin-wheel turbine 27 is formed from a cover plate 35 which has a central annular surface 37 so arranged that it contacts the transverse annular surface 38 of projection 31. The turbine 27 also includes wheel member 39 tet ice Patented Jan. 15, 19("33 which together with plate 35 provides two passages 41 (see FIG. 2). It is to be noted that extension 25 is part of wheel member 39. The right surface of the conical gas passage 29 is radially spaced from the surface of the turbine extension to form an annular gas nozzle port 44 so that gases can enter the opposed annular inlet port 45 of the turbine wheel 27 and cause rotation thereof. The annular inlet passage 45 in plate 35 expands in crosssectional area. Passages 41 terminate in a direction tangential to the wheel at exit ports 42. The cover plate 35 for the wheel member 39 is connected thereto by means of four screws 47. Screws 47 have projecting ends 49 which serve to connect other structure (to be described to the turbine 27 for rotation therewith. It is to be noted that the lateral escape of gases is possible if the annular transverse surfaces 37 and 33 are not in contact and that all of the gases will not enter the turbine inlet port 45 from nozzle 44.

Pressure access port 50 in the transverse wall 24 of the housing 11 serves as supplier of high pressure gas from conical passage 29 for other uses, if required, and otherwise will be closed by a plug (not shown).

A hollow extension 53 of the wheel member 39 projecting from the right or back side of the turbine is supported in bore 55 of arbor 57 which in turn is supported by bearings 59. The projecting ends 49 of the turbine screws 47 closely fit into four slots 61 in the left face of the arbor 57 so that the arbor is driven by the turbine but permitting axial movement of the turbine relative to the arbor. Housing 33 supports bearings 59. The arbor 57 has rotor mount or support 63 attached tothe right end cavity thereof. An electric rotor 65 is mounted on support 63 and rotates within field coils '67 forming an electric generator. It is apparent that the turbine and control (hereinafter described) can be used to drive other devices, such as pumps, compressors or gear trains, which require that the turbine speed be held at a predetermined rate.

The speed control for the above-described turbinedriven generator will now be described. The left extension 25 of the turbine wheel member 39 has two gas inlets 71 leading to passage 72 which extends axially to the interior of the right extension 53 of the wheel member. A chamber 73 formed by the right extension 53 and the transverse wall 75 of the arbor 57 thus receives high pressure gas from the conical nozzle passage 29. It is to be noted that the high pressure gas acts on the transverse turbine surface at the bottom of the right extension 53 and that the resulting axial force is opposed by a smaller axial force generated on the smaller transverse surface at the end of the left wheel extension 25. Thus, unless chamber 73 is vented, the turbine will be urged to the left and will abut the transverse housing wall so that the turbine receives all of the gases from nozzle .4-. For venting the chamber 73, a vent passage 77 is provided in the transverse wall 75 of the arbor 57. The opening of passage 77 is controlled by pintle 79 mounted in a guide hole 81 in rotor support 63. Pintle 79 is moved to the right opening vent 77 when flyweights 83 pivot outwardly on fulcrum points 85 on an inner surface of the right tubular extension 87 of the arbor 57 and act on the collar 88 of the pintle 79. The pintle normally prevents venting since it is urged to the left by spring 89 which is confined by collar 38 and rotor mount 63.

Vented gases escape from the pintle chamber by passages 91 in the arbor 57 which extend to slots 61 in the left face of the arbor. Passages 91 thus permit gases to flow to the exhaust chamber 32 and exit ports 34. When the control is venting, it is to be noted that the turbine will be moved to the right since the axial force due to pressure on the left end of extension 25 of the wheel overcomes the offsetting pressure force in vented chamber 73.

In the operation of the device, the gases generated by the electrical ignition of the solid propellant l5 creates a high pressure in chamber 19 and causes gases to move around baffle 21 through the passage 23 to nozzle passage 29. The baffle 21 shields the nozzle passage 29 and outlet from the direct gas blast and the radiation of the burning surface of solid propellant 15. The baffle 21 also acts as a centrifuge for large particles emanating rorn cartridge. The gases then move through annular nozzle 4 and expand and increase in velocity in the turbiue inlet 45 and passages 41 in the turbine wheel 2'7. The gases next discharge inja tangential direction at exit ports 52 at the periphery of the wheel 27 and create torque which accelerates the wheel and the parts driven thereby. Thus, the arbor 5'7 and the rotor 65 will be rotated to generate electricity. As the wheel 27 accelerates, it very rapidly reaches a predetermined speed at which time the fiW/eights 83 develop sufiicient force to overcome spring 87. At this stage, pintle '79 moves in a direction away from the port 77 thereby venting the chamber f3 through the two arbor passages 91. A pres sure build up in chamber '73 from inlet passage 72 is prevented because the orifice area of vent '77 is slightly larger than passage '72. The left end of extension 25 of the wheel remains subject to the high pressure in chamber 19. The high pressure on the left extension of the wheel is not now balanced by any force on the right side of the wheel resulting from the pressure in cavity 73 and the wheel moves toward the ight, since it is free to move axially Within the limits of the bore 55 of arbor 57; As the wheel moves axially, a gap. opens between the surfaces 3'7 and 38 where the wheel contacts the housing Wall around nozzle 44 and gases can move laterally. With this action, the amount of flow of gases to the wheel passages is reduced and the gasesexit directly into the exhaust cavity 32 without driving the turbine wheel. diversion of flow reduces the energy to the wheel and causes a reduction in speed.

As the turbine speed decreases below the predetermined value, the spring 89 overcomes the decreasing force of the flyweights and causes pintle 75 to move to the left, tending to close port '17. Since chamber 73 is not vented and due to the how from high pressure chamber .19 through ports 71 and passage 72, the pressure in chamber 73 increases and the axial force on the right side of the turbine within extension 53 overcomes the axial opposing force on the left extension 25 of the wheel. This results inthe turbine moving to the left and a reduction in the gap at the surfaces 37 and 38. As the gap is reduced, more gas will enter the inlet 45 of the turbine 27 and will exit through the torque-producing ports 42 of the whee. A gap position will be rapidly achieved and will satisfy the speed and load conditions. At this stage, a small bleed through port 77 will permit an intermediate gap positioning at surfaces 37 and 38. It is to be noted that extension 25 of the turbine Wheel which acts as a probe into the high pressure cavity 19 and thereby supplies high pressure gas for operation of the servo speed control also acts as a cleaning member in the nozzle throat for, any particles of the cartridge which pass the baffle 21. The cleaning is achieved by the high speed rotation of the shaft-like extension within the nozzle throat. The parts of the extension at the nozzle throat can be provided with small grooves, threads or serrations to assist in the cleaning action.

From the foregoing, it is apparent that a simple turbine arrangement is provided to give a predetermined speed control within a close tolerance range. it is to be notedthat close-fitting valves subject to malfunction have con eliminated. The axial movement of the turbine wheel to give lateral diversion of gases through the gap provides reliable control of the motive gases and simple construction. The speed responsive servo system using the axialprobe into the high pressure chamber for actuat- The.

ing the arrangement for controlling gas to the turbine provides a compact and simplified construction.

it is to be understood that changes can be made in the disclosed embodiment of the invention by persons skilled in the art without departing from the invention as set forth in the appended claims.

What is claimed is:

l. A gas turbine and control therefor comprised of a turbine having an axial inlet means, a high pressure gas supply chamber, axial gas passage means arranged to direct gases axially to said turbine inlet means from said chamber, said turbine being movable axially relative'to said passage means, said turbine inlet means and passage means defining a radially-outward flow path when said turbine is spaced from said axial gas passage means, the front side of said turbine having an axial projection extending through said passage means and into said gas supply chamber so arranged that pressurized gases in said supply chamber acting on said projection urge said turbine away from said passage means, said turbine and said projection having an axial passage for directing pressurized gas from said passage means, servo means extending from the back side of said turbine and having a control chamber fluidly connected to said last axial passage, said control chamber being so constructed that pressurized gases therein will urge said turbine toward said passage means against the force of gases on the said front projection, and vent means responsive to the speed of said turbine arranged to control the pressure in said control chamber in proportion to the speed of said turbine so that said turbine is positioned relative to saidfirst passage means by said pressure forces to permit the radial escape of gases through said radially-outward flow path and thus to maintain said turbine at'a predetermined speed.

2. A gas turbine unit and speed control therefor comprised of a radial-flow turbine wheel having laterally-ex-. tending flow paths between a front wall and a back wall, said flow paths extending from an. annular inlet at the center part of said turbine wheel to outlets in the peripheral part of said turbine wheel, passage means having a radially-centered outlet arranged to direct gases to the inlet of said turbine wheel, said turbine Wheel being movable axially relative to said passage means outlet so that a radially extending gas bleed 'gapcxists between said annular inlet and said passage means outlet whereby the quantity of gases directed to said turbine wheel can be varied, said turbine wheel having at its front'side an axial part subject to the axial force of gases in said passage means so that said turbine wheel is urged away from for the axial movement and support of said turbine wheel, said arbor being connected to said axially-movable turbine wheel for rotation therewith, said tubular exten-.

sion and said arbor providing a control chamber connected to said second axial passage, said control chamber being so constructed that gases therein will exert a greater force on the back side of said turbine wheel than the axial force from gases on said front axial part and will axially urge said turbine wheel toward said passage means outlet, said positioning means including vent means from said chamber responsive to the speed of said turbine wheel and arranged to release gases from said chamber and thus control the pressure in said control chamber in proportion to the speed of said turbine so that said turbine wheel is moved axially to provide radial escape of gases through said gap and to vary the quantity of gases received at the annular inlet of said turbine wheel and thus maintain a predetermined speed for said turbine wheel.

3. A gas turbine and speed control therefor comprised of a housing having a hi h pressure gas supply chamber separated from a turbine chamber by a transverse wall, said wall having an axial opening surrounded by a transverse annular surface, a pin-wheel turbine in said turbine chamber having a front transverse side facing said opening, said turbine wheel at the center thereof having an axial extension projecting into and through said opening into said supply chamber and radially spaced from said Opening to provide an annular gas outlet, said extension being subject to' an axial force produced by the pressure of the gases in said supply chamber said front side of said turbine having an annular surface contacting said annular, surface of said transverse wall, said pin-wheel turbine having an annular gas inlet around said extension andradially-inward of said turbine annular surface facing said annular outlet, said pin-wheel turbine and said extension having an axial probe passage opening into said gas supply chamber and extending to the back side of said turbine and conducting said pressure gas supply thereto, said turbine being mounted to move axially a small distance, control means connected to be rotated. by said turbine and having a control chamber connected to said axial passage, a portion of the back side of said turbine forming part of said control chamber and being of such size for gas from said gas supply chamber to urge. the

6 back of said turbine against the axial gas pressure force on said extension so that said turbine front side contacts said annular surface of said transverse wall, said control means being responsive to the speed of said turbine and being arranged to vent said control chamber at a predetermined speed so that the axial gas pressure force on the back side of said turbine is controlled in proportion to said speed whereby said turbine wheel is moved axially away from said annular wall surface due to gas pressure on said extension and said chamber to provide a small radial escape gap for gases between said surface and said I front transverse side.

References Cited in the file of this patent UNITED STATES PATENTS 888,415 Barber May 19, 1908 1,167,018 Pyle Jan. 4, 1916 2,206,723 I Graham et al. July 2, 1940 2,404,395 Milliken c July 23, 1946 2,695,365 McLean Nov. 23, 1954 2,794,129 Palmenberg et al. May 28, 1957 2,808,702 Dotson Oct. 8, 1957 2,832,192 Budish -2 Apr. 29, 1958 2,865,168 Zillman Dec. 23, 1958 2,917,636 Akeley Dec. 15, 1959 

1. A GAS TURBINE AND CONTROL THEREFOR COMPRISED OF A TURBINE HAVING AN AXIAL INLET MEANS, A HIGH PRESSURE GAS SUPPLY CHAMBER, AXIAL GAS PASSAGE MEANS ARRANGED TO DIRECT GASES AXIALLY TO SAID TURBINE INLET MEANS FROM SAID CHAMBER, SAID TURBINE BEING MOVABLE AXIALLY RELATIVE TO SAID PASSAGE MEANS, SAID TURBINE INLET MEANS AND PASSAGE MEANS DEFINING A RADIALLY-OUTWARD FLOW PATH WHEN SAID TURBINE IS SPACED FROM SAID AXIAL GAS PASSAGE MEANS, THE FRONT SIDE OF SAID TURBINE HAVING AN AXIAL PROJECTION EXTENDING THROUGH SAID PASSAGE MEANS AND INTO SAID GAS SUPPLY CHAMBER SO ARRANGED THAT PRESSURIZED GASES IN SAID SUPPLY CHAMBER ACTING ON SAID PROJECTION URGE SAID TURBINE AWAY FROM SAID PASSAGE MEANS, SAID TURBINE AND SAID PROJECTION HAVING AN AXIAL PASSAGE FOR DIRECTING PRESSURIZED GAS FROM SAID PASSAGE MEANS, SERVO MEANS EX- 